ProQR Therapeutics (PRQR 6.84%) is a biotechnology company based in the Netherlands that's currently developing RNA therapies for rare genetic diseases. ProQR is at the moment investigating two treatments for a rare genetic disease called Usher syndrome, QR-421a and QR-411. Though the latter is still in preclinical studies, recent phase 1/2 trial results from the STELLAR trial for QR-421a are promising. When that data was released March 24, ProQR's stock increased from $5.68 to $9.22. As of 10 a.m. April 4, the stock price is currently at $6.50.

Could these favorable results mean good things for investors? Let's look into the company and find out.

A close-up of a woman's eyes.

Image Source: Getty Images.

What is Usher syndrome?

Usher syndrome is a genetic disease that leads to worsening blindness and deafness. Mutations in the USH2A gene lead to dysfunctional usherin proteins in the eye, bringing about progressive blindness. There are 16,000 patients in the U.S. alone, and the disease is classified in three different ways depending on the symptoms. With increased awareness among healthcare professionals, the patient pool is expected to increase significantly in the next decade. The STELLAR trial focused mainly on Usher Syndrome Type 2, in which newborns experience moderate to severe hearing impairment and vision loss starts after adolescence.

The case for an investment

There are no Usher syndrome treatments currently approved by the U.S. Food and Drug Administration. QR-421a, which is administered by a healthcare provider into the back of the eye, is the most promising thing on the scene.

The STELLAR trial had four study arms. Three received one dose of QR-421a each, while the fourth received a sham procedure once. In all instances, one eye received a single dose of drug or placebo while the other served as control. Results were measured according to best corrected visual activity for those with advanced disease and most improved retinal sensitivity for those with early to moderate cases. The higher either metric is for the patient, the better his or her vision.

After the results were analyzed, the treated eyes in advanced-disease populations were found to have a 9.3-letter benefit in best-corrected visual activity compared to the untreated eyes. A letter benefit in best-corrected visual activity means the patient can read one more letter in an eye exam from a preset distance. While retinal sensitivity initially improved significantly in the treated eyes compared to the untreated eyes, there was no difference after 12 weeks. While this discrepancy may be due to a reduction in total number of patients reporting data, the best-corrected visual activity results impressed investors. According to European Medicines Agency standards, the 9.3-letter benefit in best-corrected visual activity is considered less than a letter away from establishing clinical significance among the advanced-disease patients.

Too good to be true?

Although ProQR once believed it was the only company in Western markets developing treatments for Usher syndrome, this is no longer the case. As of January 2021, notable competitors identified include Nacuity Pharmaceuticals and Editas Medicine (EDIT -1.00%) in the U.S., Nobelpharma in Japan, and Sensorion in France. However, Nacuity's antioxidant NPI-001 will report Phase 1 results in 2023, while Editas's Usher syndrome treatment, EDIT-102, has yet to commence with early-stage clinical trials. This makes ProQR currently the frontrunner with positive phase 1/2 results.

ProQR seems to be in a good position to dominate if and when it receives approval. Management intends to continue with two phase 2/3 trials to study subsets of Usher Syndrome Type 2 more meticulously. With other potential catalysts coming up -- sepofarsen and QR-1123 are both in development as treatments for other types of eye disorders -- this pipeline can offer rewards for investors willing to wait for the long run.

As of December 2020, ProQR has $92.6 million in cash and equivalents, $51.5 million in total liabilities, and $1.3 million in total revenues. Its current market cap of $415 million means that, unlike lagging behemoths in the same space such as Editas (with a market cap of $2.9 billion), ProQR could see a potential upswing of 3 to 4 times its current stock price if it secures FDA approval first. Therefore, the race between ProQR and Editas is a crucial one to keep an eye on in the Usher syndrome treatment space for the next two to three years.